NASA Uses Photo Of Earth From Saturn To Boost Space Interest

This week, NASA is trying to do its part to raise science literacy. To give people a better understanding of Earth's position in the solar system, the agency's posted a picture of our planet taken from a billion miles away, give or take 100 million miles or so. And joining me now to talk about the picture, and why NASA took it, is NPR's Joe Palca. Joe, good to see you.

JOE PALCA, BYLINE: Good to see you.

BLOCK: I'm looking at this picture - it's up on NPR.org; and we see a spectacular image of Saturn's rings, right? And then a tiny, tiny white dot.

PALCA: Right. So the picture was taken for real. I mean, they took the picture because Cassini, the spacecraft that took the picture, is in this interesting situation where Saturn is between it and the sun. So Saturn is backlit, and that makes the rings light up in some interesting ways. But they realize they had a picture of Earth in the frame, and so they made a big deal about that.

BLOCK: They're making a big deal about it; why?

PALCA: Well, I think because it's not that scientifically interesting, but it's so cool. And the woman who is in charge of the Cassini mission really got into this and made a big deal about it. Her name is Carolyn Porco. [POST-BROADCAST CORRECTION: Carolyn Porco is not in charge of the Cassini mission. She is the leader of the imaging team that took the picture of Earth.] And she actually had a video made for the occasion - or helped to have a video made for the occasion.

(SOUNDBITE OF VIDEO)

MORGAN FREEMAN: On July 19, you, me, planet Earth, and absolutely everything and everybody on it will have our picture taken from a billion miles away.

PALCA: He is. And Carolyn Porco wrote me that she was thrilled that he was able to do this in short order, which he seems to have done. And I have to say, he's wrong about one thing because people on the other side of the planet who weren't facing Saturn at that moment, people on the other side of the planet weren't in the picture.

BLOCK: They weren't in the picture.

PALCA: But the point of this whole exercise, I think, was to think of this as a teachable moment. I mean, NASA wants to draw attention to the fact that we have been able to get a billion miles in space and orbit Saturn, and take pictures back of the Earth. And it does give you perspective on the whole solar system from way out there, a perspective you can't get from, you know, even orbiting satellites 'cause even there, you only see a part of the Earth.

BLOCK: So Joe, when you look at this image, how does it compare with other images of Earth taken from outer space that we've been seeing?

PALCA: Well, most of the images that we see from outer space are more than just a dot in the picture. I mean, there are these famous pictures that the Apollo astronauts took when they were at the moon. You can see a lot of Earth rising over the moon and then, there have been pictures taken from Mars; and even last week, there were pictures taken from the Messenger, NASA's Messenger spacecraft that's been in orbit around Mercury.

But there was a really famous picture taken in 1990 from 4 billion miles away by the Voyager spacecraft, so that's further out than this picture was. And if you think this picture of Earth is unspectacular 'cause it's a single...

BLOCK: Well, it's pretty spectacular.

PALCA: Well, the dot is pretty unspectacular. It's just a little dot. But there was an even littler dot in this Voyager picture, but it inspired people because it became known as a pale blue dot. And it inspired Carl Sagan, the astronomer, to wax poetic about what it said about our place in the universe.

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CARL SAGAN: Every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species lived there on the mote of dust suspended in a sunbeam.

BLOCK: So Joe, reminder: We are motes of dust on a mote of dust. Good to keep in mind when we're all atwitter about the royal baby and things like that.